X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=cgi-auth-flexible.git;a=blobdiff_plain;f=cgi-auth-hybrid.pm;h=ec44c7a52816469be2e90d18a5892b835a31ec7f;hp=e258bdc2b613a26ff95e14702e251e06e25fa0c8;hb=2ef4865c1dd278a4c1226c8cb81416a6fff9e74c;hpb=eae7a8e60d250db29b7f7cc58afd6f46b388c26f diff --git a/cgi-auth-hybrid.pm b/cgi-auth-hybrid.pm index e258bdc..ec44c7a 100644 --- a/cgi-auth-hybrid.pm +++ b/cgi-auth-hybrid.pm @@ -1,5 +1,28 @@ # -*- perl -*- +# This is part of CGI::Auth::Hybrid, a perl CGI authentication module. +# Copyright (C) 2012 Ian Jackson. +# Copyright (C) 2012 Citrix. +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU Affero General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU Affero General Public License for more details. +# +# You should have received a copy of the GNU Affero General Public License +# along with this program. If not, see . + +use strict; +use warnings; + +package CGI::Auth::Hybrid; +require Exporter; + BEGIN { use Exporter (); our ($VERSION, @ISA, @EXPORT, @EXPORT_OK, %EXPORT_TAGS); @@ -14,12 +37,123 @@ BEGIN { our @EXPORT_OK; use DBI; +use CGI; +use Locale::gettext; + +#---------- public utilities ---------- + +sub flatten_params ($) { + my ($p) = @_; + my @p; + foreach my $k (keys %$p) { + foreach my $v (@{ $p->{$k} }) { + push @p, $k, $v; + } + } + return @p; +} + +#---------- default callbacks ---------- + +sub has_a_param ($$) { + my ($c,$cn) = @_; + foreach my $pn (@{ $r->{S}{$cn} }) { + return 1 if $r->_cm('get_param',$pn); + } + return 0; +} + +sub get_params ($$) { + my ($c) = @_; + my %p; + foreach my $name ($c->param()) { + $p{$name} = [ $c->param($name) ]; + } + return \%p; +} + +sub get_cookie_domain ($$$) { + my ($c,$r) = @_; + my $uri = new URI $r->_ch('get_url'); + return $uri->host(); +} + +sub construct_cookie ($$$) { + my ($r, $cookv) = @_; + return $r->{Cgi}->cookie(-name => $r->{S}{cookie_name}, + -value => $cookv, + -path => $r->{S}{cookie_path}, + -domain => $r->_ch('get_cookie_domain'), + -expires => '+'.$r->{S}{login_timeout}.'s', + -secure => $r->{S}{encrypted_only}); +} + +sub login_ok_password ($$) { + my ($c, $r) = @_; + my $username_params = $r->{S}{username_param_names}; + my $username = $r->_ch('get_param',$username_params->[0]); + my $password = $r->_rp('password_param_name'); + return $r->_ch('username_password_ok', $username, $password); +} + +sub do_redirect_cgi ($$$$) { + my ($c, $r, $new_url, $cookie) = @_; + my @ha = ('text/html', + -status => '303 See other', + -location => $new_url); + push @ha, (-cookie => $cookie) if defined $cookie; + $r->_print($c->header(@ha), + $r->_ch('gen_start_html',$r->_gt('Redirection')), + '', + $r->_gt("If you aren't redirected, click to continue."), + "", + $c->_ch('gen_end_html')); +} -sub new { +sub gen_plain_login_form ($$) { + my ($c,$r, $params) = @_; + my @form; + push @form, ('
{S}{form_entry_size}.'"'; + foreach my $up (@{ $r->{S}{username_param_names}}) { + push @form, ('',$r->_gt(ucfirst $up),'', + ''); + } + push @form, (''.$r->_gt('Password'),'', + ''); + push @form, ('', + '', + ''); + foreach my $n (keys %$params) { + push @form, (''); + } + push @form, ('
'); + return join "\n", @form; +} + +sub gen_login_link ($$) { + my ($c,$r, $params) = @_; + my $url = $r->url_with_query_params($params); + return (''. + $r->_gt('Log in again to continue.'). + ''); +} + +#---------- verifier object methods ---------- + +sub new_verifier { my $class = shift; - my $s = { + my $verifier = { S => { - assocdb_path => 'cah-assocs.db'; + assocdb_path => 'cah-assocs.db', assocdb_dsn => undef, assocdb_user => '', assocdb_password => '', @@ -27,119 +161,554 @@ sub new { random_source => '/dev/urandom', associdlen => 128, # bits login_timeout => 86400, # seconds - param_name => 'cah_associd', - cookie_name => 'cah_associd', # make undef to disable cookie - cgi => undef, - get_param => sub { $s->_c()->param($s->{S}{param_name}) }, - get_cookie => sub { $s->{S}{cookie_name} - ? $s->_c()->cookie($s->{S}{cookie_name}) - : '' }, - get_method => sub { $s->_c()->request_method() }, + assoc_param_name => 'cah_associd', + password_param_name => 'password', + username_param_names => [qw(username)], + form_entry_size => 60, + logout_param_names => [qw(cah_logout)], + login_submit_name => [qw(cah_login)], + loggedout_param_names => [qw(cah_loggedout)], + promise_check_mutate => 0, + get_param => sub { $_[0]->param($_[2]) }, + get_params => sub { $_[1]->get_params() }, + get_cookie => sub { $_[0]->cookie($s->{S}{cookie_name}) }, + get_method => sub { $_[0]->request_method() }, + get_url => sub { $_[0]->url(); }, + is_login => sub { defined $_[1]->_rp('password_param_name') }, + login_ok => \&login_ok_password, + username_password_ok => sub { die }, + is_logout => sub { $_[1]->has_a_param('logout_param_names') }, + is_loggedout => sub { $_[1]->has_a_param('loggedout_param_names') }, + is_page => sub { return 1 }, + handle_divert => sub { return 0 }, + do_redirect => \&do_redirect_cgi, # this hook is allowed to throw + cookie_path => "/", + get_cookie_domain => \&get_cookie_domain, + encrypted_only => 0, + gen_start_html => sub { $_[0]->start_html($_[2]); }, + gen_end_html => sub { $_[0]->end_html(); }, + gen_login_form => \&gen_plain_login_form, + gen_login_link => \&gen_plain_login_link, + gettext => sub { gettext($_[2]); }, }, - D => undef, + Dbh => undef, }; my ($k,$v); while (($k,$v,@_) = @_) { die "unknown setting $k" unless exists $s->{S}{$k}; $s->{S}{$k} = $v; } - bless $s, $class; - return $s; -} - -sub _c ($) { - my ($s) = @_; - return $s->{S}{cgi}; + bless $verifier, $class; + $verifier->_dbopen(); + return $verifier; } sub _dbopen ($) { - my ($s) = @_; - my $dbh = $s->{D}; + my ($v) = @_; + my $dbh = $v->{Dbh}; return $dbh if $dbh; - $s->{S}{assocdb_dsn} ||= "dbi:SQLite:dbname=$s->{S}{assocdb_path}"; + $v->{S}{assocdb_dsn} ||= "dbi:SQLite:dbname=$v->{S}{assocdb_path}"; my $u = umask 077; - $dbh = DBI->open($s->{S}{assocdb_dsn}, $s->{S}{assocdb_user}, - $s->{S}{assocdb_password}, { - AutoCommit => 0, RaiseError => 1, - }); + $dbh = DBI->connect($v->{S}{assocdb_dsn}, $v->{S}{assocdb_user}, + $v->{S}{assocdb_password}, { + AutoCommit => 0, RaiseError => 1, + }); die "${assocdb_dsn} $! ?" unless $dbh; - $s->{D} = $dbh; + $v->{Dbh} = $dbh; $dbh->do("BEGIN"); eval { - $dbh->do("CREATE TABLE $s->{S}{assocdb_table} (". - " associd VARCHAR PRIMARY KEY,". + $dbh->do("CREATE TABLE $v->{S}{assocdb_table} (". + " associdh VARCHAR PRIMARY KEY,". " username VARCHAR,". - " last INTEGER" + " last INTEGER NOT NULL". ")"); }; return $dbh; } -sub record_login ($$) { - my ($s,$nusername) = @_; - my $rsp = $s->{S}{random_source}; - my $rsf = new IO::File $rsp, '<' or die "$rsp $!"; - my $bytes = ($s->{S}{associdlen} + 7) >> 3; - my $nassocbin; - $!=0; - read($rsf,$nassocbin,$bytes) == $bytes or die "$rsp $!"; - close $rsf; - my $nassoc = unpack "H*", $nassocbin; - my $dbh = $s->_dbopen(); - $dbh->do("INSERT INTO $s->{S}{assocdb_table}". - " (associd, username, last) VALUES (?,?,?)", {}, - $nassoc, $nusername, time); - $dbh->do("COMMIT"); - $username = $nusername; - $assoc = $nassoc; +sub disconnect ($) { + my ($v) = @_; + my $dbh = $v->{Dbh}; + return unless $dbh; + $dbh->disconnect(); +} + +#---------- request object methods ---------- + +sub new_request { + my ($classbase, $cgi, @extra) = @_; + if (!ref $classbase) { + $classbase = $classbase->new_verifier(@extra); + } else { + die if @extra; + } + my $r = { + V => $classbase, + S => $classbase->{S}, + Dbh => $classbase->{Dbh}, + Cgi => $cgi, + }; + bless $r, ref $classbase; +} + +sub _ch ($$@) { # calls an application hook + my ($r,$methname, @args) = @_; + my $methfunc = $r->{S}{$methname}; + return $methfunc->($r->{Cgi}, $r, @args); +} + +sub _rp ($$@) { + my ($r,$pnvb) = @_; + my $pn = $r->{S}{$pnvb}; + my $p = scalar $r->_ch('get_param',$pn) +} + +sub _gt ($$) { my ($r, $t) = @_; return $r->_ch('gettext',$t); } +sub _print ($$) { my ($r, @t) = @_; return $r->_ch('print', join '', @t); } + +# pages/param-sets are +# n normal non-mutating page +# r retrieval of information for JS, non-mutating +# m mutating page +# u update of information by JS, mutating +# i login +# o logout +# O "you have just logged out" page load + +# in cook and par, +# a, aN anything including - +# t, tN temporary value (in our db, no logged in user yet) +# y, yN value corresponds to logged-in user +# n, nN value not in our db +# x, xN t or y +# - no value supplied +# if N differs the case applies only when the two values differ +# (eg, a1 y2 does not apply when the logged-in value is supplied twice) + +# "stale session" means request originates from a page from a login +# session which has been revoked (eg by logout); "cleared session" +# means request originates from a browser which has a different (or +# no) cookie. + + # Case analysis, cookie mode, app promises re mutate: + # cook parm meth form + # + # any - POST nrmuoi bug or attack, fail + # any - GET rmuoi bug or attack, fail + # any any GET muoi bug or attack, fail + # any t any nrmu bug or attack, fail + # + # - - GET O "just logged out" page + # (any other) O bug or attack, fail + # + # a1 a2 POST o logout + # if a1 is valid, revoke it + # if a2 is valid, revoke it + # delete cookie + # redirect to "just logged out" page + # (which contains link to login form) + # + # - t POST i complain about cookies being disabled + # (with link to login form) + # + # any n POST i complain about stale login form + # show new login form + # + # x1 t2 POST i login (or switch user) + # if bad + # show new login form + # if good + # revoke x1 if it was valid and !=t2 + # upgrade t2 to y2 in our db (setting username) + # set cookie to t2 + # redirect to GET of remaining params + # + # t1 a2 ANY nrmu treat as - a2 ANY + # + # y - GET n cross-site link + # show data + # + # y y GET nr fine, show page or send data + # y y POST nrmu mutation is OK, do operation + # + # y1 y2 GET nr request from stale page + # do not revoke y2 as not RESTful + # treat as y1 n GET + # + # y1 y2 POST nrmu request from stale page + # revoke y2 + # treat as y1 n POST + # + # y n GET n intra-site link from stale page, + # treat as cross-site link, show data + # + # y n POST n m intra-site form submission from stale page + # show "session interrupted" + # with link to main data page + # + # y n GET r intra-site request from stale page + # fail + # + # y n POST r u intra-site request from stale page + # fail + # + # -/n y2 GET nr intra-site link from cleared session + # do not revoke y2 as not RESTful + # treat as -/n n GET + # + # -/n y2 POST nrmu request from cleared session + # revoke y2 + # treat as -/n n POST + # + # -/n n GET n cross-site link but user not logged in + # show login form with redirect to orig params + # + # -/n n GET rmu user not logged in + # fail + # + # -/n n POST n m user not logged in + # show login form + # + # -/n n POST r u user not logged in + # fail + +sub _check_divert_core ($) { + my ($r) = @_; + + my $meth = $r->_ch('get_method'); + my $cookv = $r->_ch('get_cookie'); + my $parmv = $r->_rp('assoc_param_name'); + + my ($cookt,$cooku) = $r->_db_lookup($cookv); + my $parmt = $r->_db_lookup($parmv); + + if ($r->_ch('is_logout')) { + $r->_must_be_post(); + die unless $parmt; + $r->_db_revoke($cookv); + $r->_db_revoke($parmv); + return ({ Kind => 'REDIRECT-LOGGEDOUT', + Message => "Logging out...", + CookieVal => '', + Params => { } }); + } + if ($r->_ch('is_loggedout')) { + die unless $meth eq 'GET'; + die unless $cookt; + die unless $parmt; + return ({ Kind => 'SMALLPAGE-LOGGEDOUT', + Message => "You have been logged out.", + CookieVal => '', + Params => { } }); + } + if ($r->_ch('is_login')) { + $r->_must_be_post(); + return ({ Kind => 'LOGIN-STALE', + Message => "Stale session; you need to log in again.", + CookieVal => $r->_fresh_cookie(), + Params => { } }) + if $parmt eq 'n'; + die unless $parmt eq 't' || $parmt eq 'y'; + return ({ Kind => 'SMALLPAGE-NOCOOKIE', + Message => "You do not seem to have cookies enabled. ". + "You must enable cookies as we use them for login.", + CookieVal => $r->_fresh_cookie(), + Params => $r->_chain_params() }) + if !$cookt && $parmt eq 't'; + my $username = $r->_ch('login_ok'); + return ({ Kind => 'LOGIN-BAD', + Message => "Incorrect username/password.", + CookieVal => $cookv, + Params => $r->_chain_params() }) + unless defined $username && length $username; + $r->_db_revoke($cookv) + if defined $cookv && !(defined $parmv && $cookv eq $parmv); + $r->_db_record_login_ok($parmv,$username); + return ({ Kind => 'REDIRECT-LOGGEDIN', + Message => "Logging in...", + CookieVal => $parmv, + Params => $r->_chain_params() }); + } + if ($cookt eq 't') { + $cookt = ''; + } + die if $parmt eq 't'; + + if ($cookt eq 'y' && $parmt eq 'y' && $cookv ne $parmv) { + $r->_db_revoke($parmv) if $meth eq 'POST'; + $parmt = 'n'; + } + + if ($cookt ne 'y') { + die unless !$cookt || $cookt eq 'n'; + die unless !$parmt || $parmt eq 'n' || $parmt eq 'y'; + if ($meth eq 'GET') { + return ({ Kind => 'LOGIN-INCOMINGLINK', + Message => "You need to log in again.", + CookieVal => $parmv, + Params => $r->_chain_params() }); + } else { + return ({ Kind => 'LOGIN-FRESH', + Message => "You need to log in again.", + CookieVal => $parmv, + Params => { } }); + } + } + + if (!$r->{S}{promise_check_mutate}) { + if ($meth ne 'POST') { + return ({ Kind => 'MAINPAGEONLY', + Message => 'Entering via cross-site link.', + CookieVal => $cookv, + Params => { } }); + # NB caller must then ignore params & path! + # if this is too hard they can spit out a small form + # with a "click to continue" + } + } + + die unless $cookt eq 'y'; + die unless $parmt eq 'y'; + die unless $cookv eq $parmv; + $r->{Assoc} = $cookv; + $r->{UserOK} = $cooku; + return undef; } -sub _check ($) { - my ($s) = @_; - my $qassoc = $s->{S}{param_get}(); - if (!defined $qassoc) { - $qassoc = $s->{S}{cookie_get}(); - return undef unless defined $qassoc; - return undef unless $s->{S}{get_method}() eq 'GET'; +sub _chain_params ($) { + my ($r) = @_; + my %p = %{ $r->_ch('get_params') }; + foreach my $pncn (keys %{ $r->{S} }) { + if ($pncn =~ m/_param_name$/) { + my $name = $r->{S}{$pncn}; + die "$pncn ?" if ref $name; + $names = [ $name ]; + } elsif ($pncn =~ m/_param_names$/) { + $names = $r->{S}{$pncn}; + } else { + next; + } + foreach my $param (@$names) { + delete $p{$name}; + } } - my $dbh = $s->_dbopen(); + return \%p; +} + +sub _db_lookup ($$) { + # returns ($t,$username) + # where $t is one of "t" "y" "n", or "" (for -) + my ($r,$v) = @_; + + my $dbh = $r->{Dbh}; + my ($nusername, $nlast) = $dbh->selectrow_array("SELECT username, last". - " FROM $s->{S}{assocdb_table}". - " WHERE associd = ?", {}, $qassoc); - return undef unless defined $nusername; - my $timeout = $s->{S}{login_timeout}; - return undef unless !defined $timeout || time <= $nlast + $timeout; + " FROM $r->{S}{assocdb_table}". + " WHERE associd = ?", {}, $nassoc); + return ('') unless defined $nusername; + + my $timeout = $r->{S}{login_timeout}; + return ('n') unless !defined $timeout || time <= $nlast + $timeout; - return ($nusername, $qassoc); + return ('t') unless defined $nusername; + + # hooray + return ('y', $nusername); } -sub check ($) { - my ($s) = @_; +sub _db_revoke ($$) { + # revokes $v if it's valid; no-op if it's not + my ($r,$v) = @_; - my ($nusername, $qassoc) = $s->_check() or return undef; + my $dbh = $r->{Dbh}; - # hooray - $dbh->do("UPDATE $s->{S}{assocdb_table}". - " SET last = ?". - " WHERE associd = ?", {}, time, $qassoc); + $dbh->do("DELETE FROM $r->{S}{assocdb_table}". + " WHERE associd = ?", {}, $v); +} + +sub _db_record_login_ok ($$$) { + my ($r,$v,$user) = @_; + $r->_db_revoke($v); + $dbh->do("INSERT INTO $r->{S}{assocdb_table}". + " (associd, username, last) VALUES (?,?,?)", {}, + $v, $user, time); +} + +sub check_divert ($) { + my ($r) = @_; + my $divert; + if (exists $r->{Divert}) { + return $r->{Divert}; + } + $dbh->do("BEGIN"); + if (!eval { + $divert = $r->_check_divert_core(); + 1; + }) { + $dbh->do("ABORT"); + die $@; + } + $r->{Divert} = $divert; $dbh->do("COMMIT"); + return $divert; +} - $username = $nusername; - $assoc = $qassoc; - return $username; +sub get_divert ($) { + my ($r) = @_; + die "unchecked" unless exists $r->{Divert}; + return $r->{Divert}; } -sub logout ($) { - my ($s) = @_; +sub get_username ($) { + my ($r) = @_; + my $divert = $r->get_divert(); + return undef if $divert; + return $r->{UserOK}; +} + +sub url_with_query_params ($$) { + my ($r, $params) = @_; + my $uri = URI->new($r->_ch('get_url')); + $uri->query_form(flatten_params($params)); + return $uri->as_string(); +} + +sub check_ok ($) { + my ($r) = @_; + + my ($divert) = $r->check_divert(); + return 1 if $divert; + + my $handled = $r->_ch('handle_divert',$divert); + return 0 if $handled; + + my $kind = $divert->{Kind}; + my $cookieval = $divert->{CookieVal}; + my $params = $divert->{Params}; + + if ($kind =~ m/^REDIRECT-/) { + # for redirects, we honour stored NextParams and SetCookie, + # as we would for non-divert + if ($divert_kind eq 'REDIRECT-LOGGEDOUT') { + $params{$r->{S}{loggedout_param_names}[0]} = 1; + } elsif ($divert_kind eq 'REDIRECT-LOGOUT') { + $params{$r->{S}{logout_param_names}[0]} = 1; + } elsif ($divert_kind eq 'REDIRECT-LOGGEDIN') { + } else { + die; + } + my $new_url = $r->url_with_query_params($params); + my $cookie = $r->construct_cookie($r, $cookieval); + $r->_ch('do_redirect',$new_url, $cookie); + return 0; + } + + my ($title, @body); + if ($kind =~ m/^LOGIN-/) { + $title = $r->_gt('Login'); + push @body, $r->_gt($divert->{Message}); + push @body, $r->_ch('gen_login_form', $params); + } elsif ($kind =~ m/^SMALLPAGE-/) { + $title = $r->_gt('Not logged in'); + push @body, $r->_gt($divert->{Message}); + push @body, $r->_ch('gen_login_link'); + } else { + die $kind; + } + + $r->_print($r->_ch('start_html',$title), + @body, + $r->_ch('end_html')); + return 0; +} - if (my ($nusername, $qassoc) = $s->_check()) { - $dbh->do("DELETE FROM $s->{S}{assocdb_table}". - " WHERE associd = ?", {}, $qassoc); - $dbh->do("COMMIT"); +sub _random ($$) { + my ($r, $bytes) = @_; + my $v = $r->{V}; + if (!$v->{RandomHandle}) { + my $rsp = $r->{S}{random_source}; + my $rsf = new IO::File $rsp, '<' or die "$rsp $!"; + $v->{RandomHandle} = $rsf; } + my $bin; + $!=0; + read($rsf,$bin,$bytes) == $bytes or die "$rsp $!"; + close $rsf; + return unpack "H*", $bin; +} + +sub _fresh_cookie ($) { + my ($r) = @_; + my $bytes = ($r->{S}{associdlen} + 7) >> 3; + return $r->_random($bytes); +} + +sub check_mutate ($) { + my ($r) = @_; + die "unchecked" unless exists $r->{Divert}; + die if $r->{Divert}; + my $meth = $r->_ch('get_method'); + die "mutating non-POST" if $meth ne 'POST'; +} + +#---------- output ---------- + +sub secret_val ($) { + my ($r) = @_; + $r->check(); + return defined $r->{Assoc} ? $r->{Assoc} : ''; +} + +sub secret_hidden_html ($) { + my ($r) = @_; + return $r->{Cgi}->hidden(-name => $r->{S}{assoc_param_name}, + -default => $r->secret_val()); +} + +sub secret_cookie ($) { + my ($r) = @_; + return $r->construct_cookie($r->secret_val()); } + +__END__ + +=head1 NAME + +CGI::Auth::Hybrid - web authentication optionally using cookies + +=head1 SYNOPSYS + + my $verifier = CGI::Auth::Hybrid->new_verifier(setting => value,...); + my $authreq = $verifier->new_request($cgi_request_object); + + my $authreq = CGI::Auth::Hybrid->new_request($cgi_request_object, + setting => value,...); + +=head1 USAGE PATTERN FOR SIMPLE APPLICATIONS + + $authreq->check_ok() or return; + + blah blah blah + $authreq->check_mutate(); + blah blah blah + +=head1 USAGE PATTERN FOR FANCY APPLICATIONS + + my $divert_kind = $authreq->check_divert(); + if ($divert_kind) { + if ($divert_kind eq 'LOGGEDOUT') { + print "goodbye you are now logged out" and quit + } elsif ($divert_kind eq 'NOCOOKIES') { + print "you need cookies" and quit + ... etc. + } + } + + blah blah blah + $authreq->check_mutate(); + blah blah blah